Dresden 2011 – wissenschaftliches Programm

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Q: Fachverband Quantenoptik und Photonik

Q 30: Photonics 2

Q 30.2: Vortrag

Mittwoch, 16. März 2011, 10:45–11:00, SCH A118

Microcavity Biosensing: recent advances — •Frank Vollmer — Max Planck Institute for the Science of Light, Erlangen, Germany

Optical resonance is created by confining coherent light inside a miniature dielectric structure such that it interferes constructively. Ideally, such optical resonators (microcavities) would confine light indefinitely and real-world divergence from this condition is described by the finite cavity quality (Q) factor. Ultimate (absorption limited) Q-factors have been reported in microsphere whispering-gallery mode optical resonators where light is efficiently confined by total-internal reflection. The high Q-factor (up to 10^9) enables precise measurements of resonance frequency and changes thereof. Such changes occur, for example, due to the binding of molecules or particles to the outer surface of the microsphere cavity. Since microcavities can be immersed in a liquid without significant damping of the optical resonance, measurements of resonance frequency shifts have been exploited to construct ultra-sensitive label-free biosensor devices.

I will give an overview of our recent advances in microcavity biosensor development, which have resulted in an improvement of the detection capability down to the single particle (single virus) level. I will also highlight other modalities of microcavity biosensors, such as approaches that use resonant evanescent fields for nanoparticle trapping and manipulation, as well as for enhanced detection with plasmonic nanoparticles.